Quick-drying nail enamel compositions and method for coating a surface

ABSTRACT

The present invention relates to novel, quick drying nail enamel compositions which dry in a period of time no greater than three minutes. The compositions of the present invention preferably dry in a period no greater than about two minutes and most preferably dry in a period no greater than about 90 seconds. Compositions drying in a period less than 60 seconds are especially preferred and are also described. The compositions of the present invention have acceptable static viscosities ranging from about 400 to about 1200 centipoises and may accommodate numerous pigments to produce nail enamel compositions exhibiting favorable characteristics, including acceptable durability and gloss.

This is a continuation-in-part application of U.S. patent applicationSer. No. 311,479 entitled, "Improved Solvent Mixtures and Additive forRapid Drying of Nail Preparations and Related Methods", filed Feb. 16,1989; now abandoned.

FIELD OF THE INVENTION

The present invention relates to novel, quick drying nail enamelcompositions which dry in a period of time no greater than about threeminutes. The compositions of the present invention preferably dry in aperiod of time no greater than about two minutes and most preferably dryin a period no greater than about 90 seconds. Compositions drying in aperiod less than 60 seconds are especially preferred and are alsodescribed. The compositions of the present invention have acceptablestatic viscosities ranging from about 400 to about 1200 centipoises andmay accommodate numerous pigments to produce nail enamel compositionsexhibiting favorable characteristics, including acceptable durabilityand gloss.

The compositions of the present invention comprise a primaryfilm-forming polymer, a secondary film-forming polymer, for example, aresin which functions to strengthen the primary film-forming polymer andimprove the adhesion and gloss of the nail enamel, a plasticizer and asolvent system containing a plurality of solvents one of which isacetone in an amount no less than about 4.5% and preferably no less thanabout 13% by weight of the composition. In particularly preferredcompositions according to the present invention, acetone comprises about15% to about 25% of the total weight of the composition. Preferably, thenail enamel compositions of the present invention contain a pigment forcoloring the nail coating and a thixotropic agent, for example a claysuch as a stearalkonium hectorite, in addition to other additives suchas preservatives, stabilizers and fragrances.

BACKGROUND OF THE INVENTION

A large number of methods and compositions for beautifying andstrengthening the nails of humans are well known. Prior art methodsinclude coating the nail of an animal, including humans with acomposition including a film-forming polymer and additional ingredientssuch as pigment, plasticizer and solvents or alternatively, attachingpreformed artificial nails to human nails with adhesives. Additionalmethods include adding crosslinkable polymers to nail coatingcompositions to mend, strengthen and elongate natural nails andrepairing nails with a fabric patch.

Most nail enamel compositions presently on the market or disclosed inthe prior art dry in five minutes or longer. Even those nail enamelsthat claim to be quick-dry, i.e., dry in about five minutes are oftennot truly dry but rather are only dry to the touch. When a purportedly"dry" nail enamel of the prior art brushes up against a hard surface,the nail enamel often smudges, leaving tack.

One nail polish drying composition disclosed in U.S. Pat. No. 4,798,720prepared from commercially available top coat nail polish, acrylic nailpowder, acrylic nail primer and the adhesive "crazy glue" is describedas being used in combination with commercially available colored nailpolishes to alter the drying time of the nail polish to a period of morethan three minutes. The compositions of this patent are used as basecoats in combination with commercially available pigment containing nailpolishes. The patent claims to dry from one to seven coats of pigmentcontaining nail polish within a period ranging from about three to fiveminutes. This composition functions as a base coat or top coat andunlike the composition of the present invention, must be used incombination with a commercially available pigment nail polish to providea lasting pigmented nail enamel finish.

A nail polish which can be used to coat a natural or synthetic nailwhich dries in less than three minutes without requiring an additionalapplication of a base coat or top coat would be very desirable. Nailpolishes which dry in a period of less than 150 seconds would be evenmore desirable, as would polishes that dry in periods less than about 90seconds. A nail polish composition which would dry in a period of nogreater than about 60 seconds would be especially useful in situationswhere "drying" time is important.

Working women need to have a product which can be easily applied andwhich dries in the shortest amount of time to avoid a situation wherethey are simply wasting precious time waiting for their nail polish todry. In the manicure and pedicure industries, a colored nail polishcomposition which can dry in a period less than three minutes wouldprovide a significant advantage over the prior art compositions.

Solvent mixtures for nail enamels of the prior art have covered a widerange of compositions and have included as many as six or seven solventsto control flow, viscosity, evaporation rate and drying time of theenamel. As discussed in Peirano, "Nail Lacquers and Removers", CosmeticsScience and Technology, Interscience Publishers, Inc., 1957, solvent ormixed solvents used as the volatile portion of nail enamels are of primeimportance because of their direct effect on ease of application ofenamel, on the rate of drying and hardening, on the viscosity of theenamels and on the characteristics of the final film. According to thisreference, too rapid a rate of evaporation causes a poor flow of theenamel and also gives an uneven, streaky application. The reference alsocites the importance of proper solvent balance during the drying stagesof the lacquer. In general, due to the wide differences in evaporationrates of the solvents which are included in the prior art compositions,these compositions undergo many changes during the drying of the film.For example, during the course of evaporation of the solvent from thenail enamel on the nail, differential evaporation of the solvents withinthe composition may result in the presence of higher concentrations ofcertain solvents during drying, which in turn creates precipitation ofthe film forming polymer, resin and/or plasticizer, thereby destroyingthe integrity of the film and the appearance of the enamel. If thesolvent becomes too lean to maintain the solubility of the resin insolution, the resin will precipitate, also resulting in unacceptableresults.

The complicated character of the nail enamel mixtures of the prior artand the many possible combinations of volatile and nonvolatilecomponents had, until the unexpected discovery of the present invention,made the determination of a proper solvent balance from the perspectiveof viscosity, solubility of the individual components and theacceptability of the deposited enamel (gloss) in combination with adrying time of less than three minutes virtually impossible. Until thediscovery of the present invention, the identification of theevaporation rates of the individual solvents under various conditionshad not removed the uncertainty involved in determining a suitablesolvent balance incorporating quick-drying characteristics. Although thedesirability of a quick drying nail enamel has been a long-felt need,the rate of drying of the nail enamels of the prior art has been limitedby the aforementioned considerations. Thus, before the discovery of thepresent invention, simply incorporating low boiling solvents did notincrease the likelihood that an acceptable solvent system for nailenamels would be found or that one could obtain a nail enamelcomposition which dried in under three minutes. In the presentinvention, the use of acetone in certain weight percentages of thecomposition, in combination with numerous solvents which provideacceptable viscosity, creates a consistent quick-drying solvent systemwhich provides the nail enamel with favorable characteristics of dryingtime, viscosity, gloss, flexibility and durability.

Acetone, also known as 2-propanone, dimethylketone and beta-ketopropaneis a volatile solvent which has a boiling point of 56.5° C. and ismiscible with an extremely large number of solvents including water,alcohol, dimethylformamide, chloroform, methylene chloride, toluene,esters, including methylacetate and ethylacetate, benzene and toluene,ethers and numerous oils and hydrocarbons, among others. The uniquenessof acetone for use in the present invention resides in the fact thatacetone will interact with solvents used in nail enamels to produce asolvent system which evaporates in under three minutes.

It has surprisingly been discovered that the inclusion of specificweight percentages of acetone in combination with additional solvents incompositions for coating natural and synthetic nails produces a nailcoating composition which dries in a period of time less than threeminutes and produces a coating on a nail which is hard, flexible and hasgood wear characteristics including durability and high gloss. Moreover,the use of acetone in the volatile component of nail enamel compositionsof the present invention within specific weight percentages provides aconsistent basis upon which one of ordinary skill in the art may addadditional solvents without dramatically adversely affecting the dryingtime of the nail enamel.

OBJECTS OF THE PRESENT INVENTION

It is therefore an object of the present invention to provide apigmented nail polish composition which can be applied to natural andsynthetic nails and will dry in a period less than 3 minutes, preferablyless than two minutes, most preferably less than 90 seconds andespecially less than 60 seconds, an a clear nail enamel which can alsobe used as a basecoat or top coat which dries in less than 30 seconds.

It is a further object of the present invention to provide a generalmethod for making nail polish formulations which will dry in a periodless than three minutes.

It is still another object of the present invention to provide a nailpreparation kit comprising a base adapted for forming a coating on anatural or synthetic nail and a suitable solvent system which togetherwill provide a coating of nail enamel which dries in a period less thanthree minutes.

It is still a further object of the present invention to provide a novelmethod for coating nails with a pigmented nail polish composition whichdries in a period less than three minutes, preferably less than twominutes, most preferably less than 90 seconds and especially less than60 seconds, and a clear nail enamel which can also be used as a basecoator top coat which dries in less than 30 seconds.

It is yet additional object of the present invention to provide a numberof solvent systems which may be added to standard nail polishformulations to substantially hasten the drying of a nail enamelcomposition to a durable, hard finish exhibiting high gloss withoutadversely affecting the beneficial characteristics of the complete nailpolish formulation.

These and other objects of the present invention may be readilydetermined from the detailed description of the invention which is setforth herein.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the objects of the present invention there isprovided a nail enamel preparation comprising a fluid mixture adaptedfor drying and hardening to form a coating on a nail. The fluid mixturecomprises, in part, a plurality of solvents, one of which is acetone. Innail enamel compositions according to the present invention, acetonecomprises about 4.5% to about 35% by weight. It has surprisingly beendiscovered that acetone will interact with any number of solvents withina nail coating composition to produce a composition which will drywithin a period of time significantly shorter than would be expectedfrom the evaporation rates of the individual solvents.

The present invention therefore relates to novel compositions forcoating natural and synthetic nails which dry to a hard, flexiblecoating exhibiting favorable characteristics of durability and highgloss comprising:

a) a primary film-forming polymer;

b) a secondary film-forming polymer;

c) at least one plasticizer;

d) at least one thixotropic agent;

e) at least one pigment; and

f) an amount of acetone ranging from about 4.5% to about 35% by weightof said composition in combination with at least one additional solventhaving sufficient polarity in combination with acetone to dissolve saidprimary and secondary film-forming polymers and said plasticizer toproduce a stable composition having a static viscosity ranging fromabout 400 to about 1200 centipoises, said composition drying on anatural or synthetic nail surface within a period of time less thanthree minutes.

In addition to the components set forth above, the compositions of thepresent invention may further comprise additional agents, for example,fragrances and preservatives.

It is a surprising result that the nail enamel compositions embraced bythe present invention which include significant quantities of solventswhich include acetone and which have a static viscosity of about 400 toabout 1200 centipoises, optimally, about 800 centipoises, consistentlydry in less than three minutes. It is particularly surprising that theinclusion of certain weight percentages of acetone in combination withnumerous solvents which do not otherwise dry within a period less thanthree minutes will produce nail enamel compositions which will dry in aperiod of time less than three minutes, for example, two and a halfminutes minutes, 90 seconds or even less than 1 minute. In certainparticularly preferred compositions according to the present inventionwhich do not include thioxotropic agents and pigments, an especiallyfast drying base coat or top coat formulation is presented comprisingabout 18% to about 35% by weight acetone, preferably about 24% to about35% by weight acetone, in combination with other solvents, primaryfilm-forming polymer, secondary film-forming polymer and at least oneplasticizer. Such compositions, which can be used as base coats, topcoats or clear enamels, dry in a period of time less than about 30seconds.

It is also surprising that the solvent combinations which are used inthe compositions of the present invention dry in such a short period oftime in a uniform fashion without streaking or precipitation of thesolid material. The resulting enamel coat is uniform, hard and flexibleand exhibits favorable durability and high gloss.

In accordance with the present invention, the nail enamel compositionsof the present invention include a primary film-forming polymer. Theprimary film-forming polymer is used as the base material for the nailenamel. In the present invention numerous film-forming polymers may beused as the primary film-forming polymer including cellulose acetate,cellulose acetatebutyrate, ethyl cellulose, numerous vinyl polymers aswell as a number of methacrylate and acrylate type polymers. Preferably,nitrocellulose is used as the film-forming polymer in the presentinvention.

In addition to the primary film-forming polymer, the compositions of thepresent invention also include an amount of a secondary film-formingpolymer effective to strengthen the primary film-forming polymer andprovide the enamel coating with acceptable gloss and adhesioncharacteristics. Exemplary secondary film-forming polymers or resinswhich may be used in the present invention include, for example, dryingand nondrying alkyd resin, polyvinyl resins, for example polyvinylacetate, polyester resins, acrylic and methacrylic resins andarylsulfonamide-formaldehyde resins, for example toluenesulfonamide-formaldehyde resin. These secondary film-forming polymersare added to the primary film-forming polymers of the present inventionto strengthen and add acceptable wear characteristics to the primaryfilm-forming polymer. Toluene sulfonamide-formaldehyde resin, acondensation product of formaldehyde and toluene sulfonamide isespecially preferred for use as a secondary film-forming polymer in thepresent invention.

In addition to the primary and secondary film-forming polymers thecompositions according to the present invention also comprise at leastone plasticizer, preferably for example, dibutyl phthalate and mostpreferably a mixture of dibutyl phthalate and camphor to addcharacteristics of flexibility to the nail coating. Certain secondaryfilm-forming polymers, for example, toluene sulfonamide/epoxy resin andtoluene sulfonamide/epoxy resin butyl acetate, available fromTelechemische, Newburgh, N.Y., which have acceptable plasticizationcharacteristics may be used in certain embodiments of the presentinvention without the need to include a separate plasticizer.

In addition to the above-described components, the compositions of thepresent invention may additionally comprise a clay thixotropic agent,for example, stearalkonium hectorite, for example, the Bentones™,available from NL Industries, New Jersey, U.S.A. and in addition acoloring substance or pigment to give the preparation a cosmeticallyacceptable shade and to opacify the film.

In addition to the components set forth above, the compositions of thepresent invention may also include further additives includingstabilizers, preservatives, fragrances and antioxidants.

To provide acceptable static viscosities within the range of about 400to 1000 centipoises, the nail enamel compositions of the presentinvention generally comprise about 50% to about 75% by weight solvent,preferably about 60% to about 70% by weight solvent, and most preferablyabout 64% to about 68% by weight solvent.

In addition to the disclosed weight percentages of acetone which areused in the present invention, other exemplary solvents include forexample, ethyl acetate, methyl acetate, methanol, ethanol, isopropanol,n-butanol, n-butyl acetate, methylchloroform, methylene chloride,toluene, xylene, additional aromatic (containing phenyl groups) solventsand mixtures thereof, among others, including amyl acetate, numerousethers, numerous ketones including methylethylketone and alkanesincluding pentane, cyclopentane, hexane, and cyclohexane, among others,in varying weight percentages. In addition to the above-named solvents,other solvents which may be used in the present invention include, forexample, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, amongothers. High boiling solvents, for example, cellosolve, butyl cellosolveacetate, cellosolve acetate, methyl cellosolve acetate, butylcellosolve, ethyl cellosolve and phenylated solvents including xylenemay also be used. Of course, these high-boiling solvents, because oftheir tendency to increase drying times are included in weightpercentages in compositions of the present invention in amountsconsistent with producing a nail composition which dries in less thanthree minutes. One of ordinary skill in the art will know to vary theweight percentages of acetone and the other solvents used incompositions of the present invention within the teachings of thepresent invention to produce a large number of acceptable solventcombinations for use in nail enamel compositions which dry in a periodof less than three minutes.

In the present invention, it has been found advantageous to includeacetone in amounts ranging from about 4.5% to about 35%, preferablyabout 13% to about 30% and most preferably about 15% to about 25% byweight acetone. In certain embodiments of the present invention in whichpigment and the thixotropic agent Bentone RSNC™ is included, about 18%by weight acetone has been found to be quite advantageous.

In addition to acetone, the present invention may also include analcohol, for example, ethanol, isopropanol, methanol or n-butanol inamounts generally less than 10% and preferably less than about 5% byweight of the nail enamel composition. The compositions of the presentinvention also generally include an ester, preferably an ester of aceticacid such as methyl acetate, ethyl acetate, propyl acetate, n-butylacetate and mixtures of these esters in amounts ranging up to about 50%by weight of the nail enamel compositions, and preferably about 20% toabout 30% by weight of the nail enamel compositions.

Compositions of the present invention may also include an aromaticdiluent, for example, toluene, xylene and certain naphtha derivatives.Because of the regulatory implications of using certain of thesesolvents, a number of substitutes for toluene may be included incompositions of the present invention. Substitutes for toluene includefor example, esters of acetic acid such as methyl acetate, ethyl acetateand n-butyl acetate, chlorinated hydrocarbons, for example, methylenechloride, methylchloroform, various ketones other than acetone includingmethylethyl ketone and various hydrocarbons including hexane,cyclohexane and pentane, among others.

It is an especially surprising result that acetone in an amount rangingfrom about 4.5% to about 35% by weight of the final composition incombination with a solvent combination which otherwise does not dry orevaporate within a period of three minutes on a human or artificial nailwill dry in a time period less than three minutes. The solvents whichare included with acetone in the present invention are chosen for theirability, in combination with acetone, to dissolve the primaryfilm-forming polymer, the secondary film-forming polymer and theplasticizer and for their ability to provide a final static viscosity incombination with the solids of the compositions of the present inventionincluding pigment and thixotropic agent in the range of about 400 toabout 1200 centipoises, preferably about 800 centipoises.

The present invention also relates to a nail preparation kit comprisinga polymer base adapted for drying and hardening to form a pigmentedcoating on a nail upon mixture of the base with a suitable solventmixture, the solvent mixture comprising an amount of acetone comprisingat least about 4.5% to about 35% by weight of the final nail enamelcomposition including solids in combination with a plurality of solventswhich, include acetone and which dissolve a primary film-formingpolymer, a secondary film-forming polymer and a plasticizer, thecomposition having a final static viscosity ranging from about 400 toabout 1200 centipoises, preferably about 800 centipoises. In addition toprimary film-forming polymer, secondary film-forming polymer andplasticizer, the polymer base additionally comprises a thixotropic agentand at least one pigment and optionally, additional additives includingpreservatives and fragrances, among others. In this nail preparation kitaspect of the present invention, the polymer base comprises about 25% toabout 50% by weight of the final nail enamel composition to be appliedto the nail and the solvents comprise about 50% to about 75% by weightof the composition, preferably about 60% to about 70% by weight and mostpreferably about 64% to about 68% by weight solvent. The nailpreparation kit of the present invention also includes top coat,basecoat and clear nail enamel compositions which contain at least about18% to about 35% by weight acetone, preferably at least about 24% toabout 35% by weight acetone and an absence of pigment and thixotropicagent. These compositions dry in a period of time no greater than about30 seconds.

In still another aspect of the present invention, solvent mixturesparticularly adapted for use in combination with pigmented polymer basesfor use in nail enamel compositions are also disclosed. In this aspectof the present invention, a solvent mixture comprises acetone in anamount equal to about 6% to about 70% by weight of the solvent mixtureand at least one additional solvent to produce a solvent mixture which,in combination with a polymer base adapted for use in pigmented nailenamel preparations, provides a nail enamel preparation containing atleast about 4.5% to about 35% by weight acetone, said nail enamelcomposition having a static viscosity ranging from about 400 to about1200 centipoises and drying in a period less than three minutes to ahard, flexible pigmented surface having acceptable wear characteristicsincluding durability and high gloss. Solvent systems for use inbasecoat, top coat and clear enamel compositions containing at leastabout 24% by weight acetone up to about 70% by weight acetone.

In accordance with a further aspect of the present invention, thepresent invention includes a process for making the pigmented nailenamel compositions of the present invention. In this aspect of thepresent invention nail enamel compositions of the present invention areformulated by first mixing a number of solvents including an amount ofacetone equal to about 6% to about 70% by weight of the solvent mixtureto produce a solvent mixture. Thereafter, a primary film-formingpolymer, a secondary film-forming polymer and at least one plasticizeris added stepwise in any order in conjunction with vigorous mixing,until a viscous solution is produced. The compositions producedaccording to this method can be used as colorless nail polishes oralternatively, as base coat and top coat formulations in conjunctionwith colored nail polishes. After the viscous solution is produced, athixotropic agent, for example, stearalkonium hectorite, is added to theabove-described mixture in conjunction with vigorous stirring (understrong shearing force with a Hoffmeyer industrial mixer) generally for aperiod of about at least one hour to produce a gelled mixture. In thelast step, one or more pigments are added to the above gelled mixture toproduce the rapid drying mixtures according to the present invention.The final composition produced by the method according to the presentinvention obtains a final static viscosity ranging from about 400 toabout 1200 centipoises.

While it is possible to produce the compositions of the presentinvention following the general procedures of the method aspect of thepresent invention, it is clearly preferred that all mixing of the nailenamel compositions and especially those containing stearalkoniumhectorite thixotropic agent and pigment, be performed under high shearspeed. Therefore, one of the more important aspects of the method of thepresent invention includes the use of vigorous stirring at high shearspeed, for example using a Hoffmeyer industrial mixer for a period oftime sufficient to produce a thixotropic gel, generally at least aboutone hour and preferably at least about two hours.

DETAILED DESCRIPTION OF THE INVENTION

Compositions of the present invention for coating a natural or syntheticnail comprise the following ingredients:

a) a primary film-forming polymer;

b) a secondary film-forming polymer;

c) at least one plasticizer;

d) at least one thixotropic agent;

e) at least one pigment; and

f) an amount of acetone ranging from about 4.5% to about 35% by weightof said composition in combination with at least one additional solventhaving sufficient polarity in combination with said acetone to dissolvesaid primary and secondary film-forming polymers and said plasticizer toproduce a stable composition having a static viscosity ranging fromabout 400 to about 1200 centipoises, said composition drying on anatural or synthetic nail within a period of less than three minutes.

In certain embodiments, the compositions according to the presentinvention contain an absence of thixotropic agent and pigment andcontain at least about 18% by weight acetone, preferably at least about24% by weight acetone so that the drying time is less than about 30seconds. These compositions may be used as clear nail enamel oralternatively as base coats or top coats for application to nails.

In addition to the above components, the compositions according to thepresent invention may further comprise one or more additional agents,for example, stabilizers, fragrances, anti-oxidants and preservatives.

The compositions of the present invention contain a primary film-formingpolymer for example, cellulose acetate, cellulose acetate-butyrate,ethyl cellulose, numerous vinyl polymers as well as a number ofmethacrylate and acrylate type polymers. The preferred primaryfilm-former for use in the present invention is nitrocellulose.Nitrocellulose for nail enamel compositions of the present invention isof two standard types designated respectively, RS and SS. RSnitrocellulose, available from a number of manufacturers includingS.N.P.E. of Bergerac, France and Hercules Inc., of Philadelphia, Pa.,U.S.A., the preferred nitrocellulose, is available in a wide range ofviscosities. Although a number of different nitrocellulose film-formersmay be used in compositions of the present invention, it is preferredthat nitrocellulose RS 1/2 second, available from Hercules be used inthe compositions of the present invention. In general, the primaryfilm-forming polymer is included in compositions of the presentinvention in amounts effective to provide toughness, hardness,resistance to abrasion and its solvent release and a film thickness, incombination with secondary film-forming polymers and plasticizers ofabout 2.5 mil to 6 mil, preferably about 3 mil. In general, the amountof primary film-forming polymer comprises about 5% to about 25% byweight of the compositions, preferably about 9.0% to about 20% by weightof the compositions and most preferably about 10% to about 15% by weightof the composition.

In addition to the primary film-forming polymer, the compositions of thepresent invention also include a secondary film-forming polymer which isadded to the primary film-forming polymer for its ability to providestrength, gloss and adhesion. Exemplary secondary film-forming polymerswhich may be used in the present invention include alkyd resins (bothdrying and nondrying), polyvinyl resins, for example, polyvinyl acetate,polyester resins, acrylic and methacrylic resins andarylsulfonamide-formaldehyde resins. Toluene sulfonamideformaldehyderesin, a condensation product of formaldehyde and toluene sulfonamide isespecially preferred for use as a secondary film-forming polymer in thepresent invention. In general, the amount of secondary film-formingpolymer used is that amount effective to strengthen the primaryfilm-forming polymer and provide an effective gloss and adhesion. One ofordinary skill in the art will be able to determine the amount ofsecondary film-forming polymer which may be added to the compositions ofthe present invention to produce the desired effect without engaging inundue experimentation. However, in general, the amount of secondaryfilm-forming polymer to be used in the present invention ranges fromabout 4.0% to about 13% by weight of the composition, preferably about7.0% to about 10% by weight and most preferably about 9.0% by weight ofthe composition.

In addition to primary and secondary film-forming polymers, thecompositions according to the present invention also include at leastone plasticizer. Plasticizers for use in the present invention are addedto soften and plasticize the primary film-forming polymer. The choice ofplasticizer for a nail enamel composition may vary as a function of thecolor, odor, effect on viscosity of the enamel, effect on the dryingrate, the amount needed to meet flexibility requirements, the volatilityof the plasticizer and compatability with the other components of thecompositions. Plasticizers for use in the present invention includetricresyl phosphate, diamylphthalate, dibutyl phthalate, diethylphthalate, dibutyl tartrate, benzyl benzoate, tributyl phosphate, butylacetyl ricinoleate, butyl glycolate, dioctyl phtalate, butyl stearate,triphenyl phosphate, triethyl citrate, camphor, castor oil and dibutoxyethylphthalate, among others. Preferred plasticizers for use in thepresent invention include dibutyl phthalate, camphor and especiallymixtures of dibutyl phthalate and camphor. In general, plasticizer isincluded in the compositions of the present invention in an amountsufficient to provide acceptable flexibility to nail enamel on the humanor synthetic nail surface. By acceptable flexibility, we mean that thecomposition will evidence no cracking when a 6 mil film which has beendried on an aluminum strip surface for at least two hours is bent arounda 0.25" mandrel (available from Gardner Corporation, Florida, U.S.A.).In general, the amount of plasticizer for use in the compositions of thepresent invention ranges from about 2.0% to about 7.5%, preferably about3.0 to about 6.0% and most preferably about 3.5 to about 5.5% by weight.

In addition to the primary and secondary film-forming polymers andplasticizer, the compositions according to the present invention alsoinclude a solvent mixture containing acetone in an amount ranging fromabout 6.0% to about 70% of the total weight of the solvent. Because thetotal amount of solvent ranges from about 50% to about 75% by weight ofthe nail enamel compositions of the present invention, acetone thereforecomprises about 4.5% to about 35% by weight of the total weight of thenail enamel compositions. The amount of acetone included in thecompositions is selected to create an interaction with the othersolvents that are used in the compositions. It has surprisingly beenfound that acetone used in combination with additional solvents willresult in a nail enamel composition which will dry in less than threeminutes. By "dry" we mean that the nail enamel compositions willevidence no tack with a cotton swap ("Q-tip") when drawn down on to a 3mil thick layer on lineta cards (Lineta Company, Hohokus, N.J.) at roomtemperature and a relative humidity of about 50 to 55%. Of course, thedrying time of a nail enamel formulation will vary as a function of thetemperature and relative humidity of the ambient atmosphere.

Other solvents which may be used in the compositions of the presentinvention include, for example, ethyl acetate, methanol, ethanol,isopropanol, n-butanol, n-butyl acetate, methyl chloroform, methylenechloride, toluene and mixtures thereof, among others, including amylacetate, numerous ethers, and alkanes including pentane, hexane, andcyclohexane and mixtures thereof among others, in varying weightpercentages. In addition to the above-named solvents, other solvents maybe used in the present invention include, for example, methyl acetate,cyclopentane and tetrahydrofuran, including mixtures thereof, amongothers. High boiling solvents, for example, cellosolve, butyl cellosolveacetate, cellosolve acetate, methyl cellosolve acetate, butylcellosolve, ethyl cellosolve and phenylated solvents including xylenemay also be used.

Of course, the high-boiling solvents, have a tendency to increase dryingtimes and therefore are included in weight percentages in compositionsof the present invention in amounts consistent with producing a nailcomposition which dries in less than three minutes. In many cases, theamount of high boiling solvent is included in an amount no greater thanabout 5.0% and often in an amount significantly less than about 5% byweight of the final composition. One of ordinary skill in the art willknow to vary the weight percentages of acetone and the other solventsused in compositions of the present invention within the teachings ofthe present invention to produce a large number of acceptable solventcombinations for use in nail enamel compositions which dry in a periodof less than three minutes.

In addition to acetone, the inclusion of methylchloroform incompositions of the present invention in many cases may have abeneficial effect on the drying time. However, the effect ofmethylchloroform is not nearly as great as that caused by the disclosedweight percentages of acetone.

While not being limited by way of theory, it is believed that acetone isresponsible for creating an interaction with the other solvents utilizedin the present invention to substantially reduce the drying times ofnail compositions to below three minutes. Such interaction may be due tothe universality of solvency that acetone displays with almost anysolvent. It is quite surprising that a combination of solvents which, incombination with the non-volatile components of the present invention,normally do not dry within a period even close to three minutes, driesin a period under three minutes. Even more surprising is the fact thatthe inclusion of at least about 18% by weight acetone in combinationwith other solvents will produce a pigmented nail enamel compositionwhich will dry within about 60 seconds and a clear nail enamelcomposition containing an absence of pigment and thixotropic agent whichdries in less than 30 seconds.

The amount of acetone included within the compositions according to thepresent invention varies between about 4.5% and about 35%. This rangerepresents a guideline for inclusion of acetone in compositionsaccording to the present invention. The lower limit of this rangerepresents the least amount of acetone that is generally used to producea nail enamel which dries in less than three minutes. The upper limit ofthis range represents the amount of acetone above which begins toproduce an unacceptable streaking effect on the enamel during coating.Compositions according to the present invention include an amount ofacetone generally falling within this range, the amount of acetone to beinclude being determined by the desired drying time and the additionalsolvents which are added to produce the desired viscosity and flowcharacteristics.

In many of the commercial nail enamel preparations on the market,toluene, xylene or other aromatic solvent is included in varying amountsas a diluent. In an additional aspect, the present invention alsorelates to quick-drying compositions which have acceptablecharacteristics and which exclude toluene and other aromatic solventswhich may not be acceptable for inclusion in cosmetic formulations byregulatory agencies. In this aspect of the present invention, toluene orother aromatic solvent is replaced with another solvent, especially forexample, a ketone-containing composition other than acetone such asmethyl ethyl ketone, one of the esters of acetic acid such as ethylacetate or methyl acetate, chlorinated hydrocarbons for example,methylchloroform, methylene chloride, chloroform and other solvents, forexample, hexane, cyclohexane, pentane and heptane, as well as numerousadditional solvents.

In compositions of the present invention which contain an absence ofpigment and thixotropic agents, virtually any low boiling solvent, i.e.,a solvent which has a boiling point less than about 90°C. may besubstituted for toluene or other aromatic (containing a phenyl group)solvent provided that the primary film-forming polymer, secondaryfilm-forming polymer and plasticizer are placed in solution. Incompositions without thixotropic agent or pigment, numerous high boilingsolvents may also be used, but care must be taken to limit the use ofsuch solvents to low levels to avoid increasing the drying time aboveacceptable limits. An acceptable drying time for compositions whichcontain an absence of pigment and/or thixotropic agent is less than 30seconds. In order to produce such a fast drying time, in this aspect ofthe present invention, these nail enamel compositions, contain at least18% by weight acetone and preferably at least about 24% acetone.Following the guidelines and descriptions of the present applicationwill enable one of ordinary skill in the art to readily substitute fortoluene and still maintain the drying times within acceptable limits.

In compositions of the present invention which contain a pigment andpreferably, a thixotropic agent, the choice of solvents which maysubstitute for the toluene or other aromatic diluent is more limited. Inthese compositions, care must be taken to substitute a solvent havingsimilar polarity to toluene. Because the use of thixotropic agent inpreferred compositions of the present invention is often advantageousand because the use of thixotropic agent may be affected by the polarityof the solvents chosen, care must be taken when substituting for toluenein compositions according to this aspect of the present invention. Incertain cases, the use of very large quantities of non-polar solvents,for example, hydrocarbons such as hexane, heptane and pentane as well asother non-polar solvents, without the inclusion of sufficient amounts ofmore polar solvents, may affect the ability of the thixotropic agent toform a gel, preferably a colloidal gel. In addition, the inclusion oflarge percentages of highly polar solvents, for example, methanol,ethanol and isopropanol may adversely affect the ability of thethixotropic agent to form a gel, preferably a colloidal gel. Therefore,polar substitutes for toluene in this aspect of the present inventionshould be limited to no greater than about 25% by weight of the totalweight of the composition and preferably no greater than about 18% byweight of the composition. Preferably, substitutes for toluene in thisaspect of the present invention include esters of acetic acid, forexample methyl acetate, ethyl acetate and n-butyl acetate, ketones otherthan acetone, including methyl ethyl ketone, chlorinated hydrocarbons,for example, methylene chloride, chlorform and methylchloroform as wellas other solvents of similar polarity to toluene.

In certain compositions according to the present invention, a pigmentand a thixotropic agent is also added. Pigments are added to thecompositions to provide cosmetically acceptable shades and to opacifythe films. Pigments for use in the present invention include for examplered pigments, including for example, D & C red Nos. 10, 11, 12 and 13, D& C red No. 7, TOB-BON maroon (D & C red No. 34). Other pigments whichmay be used in compositions according to the present invention includethe Lake pigments, for example, D & C yellow No. 5 Lake, D & C Red No. 2Lake, and Ext. D & C Red No.2 Lake. In addition to the above-namedpigments, additional pigments can include cosmetic-grade or purifiedtitanium dioxide (white), yellow and red iron oxides, iron blue, ironblack, ultramarine blue, chromide oxide greens, carbon black orlampblack (generally, in minute quantities).

In addition to the above-named pigments, iridescent additives may beincluded for example, "pearl essence", which is a suspension ofcrystalline guanine in nitrocellulose and solvents as well as otheradditives which will affect the appearance of the pigment. Although theamount of pigment in compositions of the present invention will vary asa function of the type of pigment and other components included in thecompositions, in general, pigments are included in an amount rangingfrom about 0.025 to about 4.0% by weight and preferably in an amountranging from about 0.5 to about 1% by weight of the composition.

When pigments are included in compositions according to the presentinvention, it is useful to include a thixotropic agent for enhancing thesuspension of pigment in the other components of the composition.Although a number of thixotropic agents generally used in the nailenamel art may be used to produce compositions according to the presentinvention, preferred thixotropic agents include the thixotropic clays,especially stearalkonium hectorites. Particularly preferredstearalkonium hectorites for use in the present invention include theBentones™, including Bentone 27™, available from NL Industries, NewJersey, U.S.A. An especially preferred stearalkonium hectoritecontaining thixotropic agent for use in the present invention is BentoneRSNC™, available from Penn Color, Doylestown, Pa. U.S.A. Bentone RSNC™is a composition containing about 25% by weight stearalkonium hectoritemilled to about 5 microns in nitrocellulose and plasticizer (camphor).In particularly preferred compositions according to the presentinvention, thixotropic agent is included in an amount sufficient toproduce a gel, preferably a colloidal gel. In general, the purethixotropic agent without the additives, is included in amounts rangingfrom about 2% to about 5% by weight of the composition, preferably about2 to about 4% and most preferably about 2 to 3% by weight of thecomposition.

The use of a preferred thixotropic agent, especially Bentone RSNC™ incombination with pigment for use in compositions of the presentinvention in combination with a sufficiently polar solvent mixture andmixing under shearing force (Hoffmeyer industrial mixer for a period ofat least one hour, preferably two hours) results in a gel which servesto suspend the pigment and maintain the pigment in suspension forextended periods of storage. In this aspect of the present invention,compositions according to the present invention include Bentone RSNC™ insufficient quantity to produce a gel are storage stable, i.e., theymaintain their viscosity, consistency and pigment in suspension withoutthe need for significant shaking even after extended periods of storage.

It is important to note that the acetone-containing solvent mixtureschosen for use in compositions according to the present invention whichcontain this thixotropic agent should be of sufficient polarity tofavorably interact with the stearalkonium hectorite to produce a gel.The gel which is produced in preferred embodiments of the presentinvention results in a suspension of pigment which will not settle tothe same extent as nail enamel compositions which do not contain such agel suspension. The compositions of the present invention which utilizestearalkonium hectorite thixotropic agents are therefore storage stableand may be applied to the nail even after periods of long storage by asimple shaking of the container before application. There is no need toinclude for example, a steel ball to enable a vigorous shaking of thecomposition before application as is required by many of thecompositions of the prior art.

In addition to the above-described components, the compositions of thepresent invention may also include additional additives includingstabilizers, preservatives, anti-oxidants and fragrances, depending uponthe intended result. These components are well known in the art and maybe included in amounts well within the teachings of the art.

The nail enamel compositions of the present invention havecharacteristics of quick-drying, flexibility, durability, adequateviscosity and high gloss. The pigmented compositions of the presentinvention dry in a period of less than three minutes. By "dry" we meanthat the compositions will evidence no tack (absence of smudging) aftera three minute drying period at room temperature and a relative humidityof 50-55%. Compositions of the present invention are also flexible,i.e., the composition will evidence no cracking when a 6 mil film whichhas been dried on an aluminum strip surface for at least two hours isbent around a 0.25" mandrel (available from Gardner Corporation,Florida, U.S.A.). Compositions of the present invention are also durableand do not chip or crack for a period of at least about three days ofwearing on a human or synthetic nail.

The viscosities of compositions of the present invention arecommercially acceptable. In general as previously indicated, the staticviscosities of the compositions of the present invention fall within therange of about 400 to about 1200 centipoises, preferably about 800centipoises. For purposes of defining the present invention, staticviscosities are determined on a Brookfield RVF viscometer after at least24 hours of incubation at 25° C. using a spindle #3 at 25° C. and 20RPM. In addition to static viscosities, shaken viscosities are alsogenerally commercially acceptable. Shaken viscosities differ from staticviscosities and are determined in the following two ways. First, shakenviscosities are determined using a Brookfield LVF viscometer, spindle #3at 60 RPM after the compositions are shaken for a brief period. Thecompositions of the present invention exhibit a shaken viscosity underthese conditions generally ranging from about 250 to about 500centipoises, with an optimum of about 400 centipoises. Additional shakenviscosities are determined at 6 RPM on a Brookfield LVF viscometer,spindle #3 at 25° C. Viscosities of the compositions of the presentinvention under these conditions generally range from about 800 to about1200 centipoises, with an optimum of about 1000 centipoises.

Compositions of the present invention generally exhibit an acceptablegloss ranging from about 70 to about 95% reflection of light asdetermined by a Glossguard Meter (6 mil thick coating on an aluminumsurface). Preferably, the compositions of the present invention exhibita gloss ranging from about 85 to about 95% reflection of light asdetermined by a Glossguard Meter.

The present invention also relates to a nail preparation kit comprisinga polymer base adapted for drying and hardening to form a pigmentedcoating on a nail upon mixture of the base with a suitable solventmixture, the solvent mixture comprising an amount of acetone comprisingat least about 4.5% to about 35% by weight of the final nail enamelcomposition including solids in combination with a plurality of solventswhich, in combination with acetone dissolve the primary film-formingpolymer, the secondary film-forming polymer and the plasticizer, thecomposition having a final static viscosity ranging from about 400 toabout 1200 centipoises, preferably about 800 centipoises. In addition toprimary film-forming polymer, secondary film-forming polymer andplasticizer, the polymer base additionally comprises a thixotropic agentand at least one pigment and optionally, additional additives includingpreservatives and fragrances, among others. In this nail preparation kitaspect of the present invention, the polymer base comprises about 25% toabout 50% by weight of the final nail enamel composition to be appliedto the nail and the solvents comprise about 50% to about 75% by weightof the composition, preferably about 60% to about 70% by weight and mostpreferably about 64% to about 68% by weight solvent. The nailpreparation kit of the present invention also includes top coat,basecoat and clear nail enamel compositions which contain at least about18% to about 35% by weight acetone, preferably at least about 24% toabout 35% by weight acetone and an absence of pigment and thixotropicagent. These compositions dry in a period of time no greater than about30 seconds.

To use the nail preparation kit of the present invention, the user willadd the solvent mixture to the base formula which contains primaryfilm-forming polymer, secondary film-forming polymer and plasticizer.After thoroughly mixing the solvent with the three solid ingredients,the resulting mixture may be used a basecoat, top coat, or clear nailenamel. Alternatively, if a pigmented nail enamel composition isdesired, after thorough mixing of the solvent, primary film-formingpolymer, secondary film-forming polymer and plasticizer, thixotropicagent is added and the mixture vigorously shaken for a period of timesufficient to produce a homogeneous mixture. Thereafter, pigment isintroduced into the mixture and the pigment-containing mixture isthoroughly mixed until a homogeneous mixture is realized. The finalproduct may then be stored or coated onto a natural or synthetic nailsurface.

In still another aspect of the present invention, solvent mixturesparticularly adapted for use in combination with pigmented polymer basesfor use in nail enamel compositions are also disclosed. In this aspectof the present invention, a solvent mixture comprises acetone in anamount equal to about 6% to about 70% by weight of the solvent mixtureand at least one additional solvent having a polarity sufficient toproduce a solvent mixture which, in combination with a polymer baseadapted for use in nail enamel preparations comprising a primary,film-forming polymer, a secondary film-forming polymer, at least oneplasticizer, a thioxotropic agent and pigment, provides a nail enamelpreparation containing at least about 4.5% to about 35% by weightacetone having a static viscosity ranging from about 400 to about 1200centipoises and drying in a period less than three minutes to a hard,flexible pigmented surface having acceptable wear characteristicsincluding durability and high gloss. Solvent systems for use inbasecoat, top coat and clear enamel compositions contain at least about24% by weight acetone up to about 70% by weight acetone.

The present invention also relates to methods of making the compositionsof the present invention. In this aspect of the present invention nailenamel compositions of the present invention are formulated by firstmixing a number of solvents including an amount of acetone equal toabout 6% to about 70% by weight of the solvent mixture to produce asolvent mixture. Thereafter, a primary film-forming polymer, a secondaryfilm-forming polymer and at least one plasticizer is added step-wise inany order in conjunction with vigorous mixing until a viscous solutionis produced. The compositions produced according to this method can beused as colorless nail polishes or alternatively, as base coat and topcoat formulations in conjunction with colored nail polishes. After theviscous solution is produced, a thixotropic agent, for example,stearalkonium hectorite, is added to the above-described mixture inconjunction with vigorous stirring (under strong shearing force with aHoffmeyer industrial mixer) generally for a period of about at least onehour to produce a gelled mixture. In the last step, one or more pigmentsis added to the above gelled mixture to produce the rapid dryingmixtures according to the present invention. The final compositionproduced by the method according to the present invention obtains afinal static viscosity ranging from about 400 to about 1200 centipoises.Certain compositions of the present invention produced in this wayincluding Bentone RSNC™ are storage stable and do not require thevigorous shaking that the prior art compositions often require afterextended periods of storage.

The following examples are provided to illustrate the present inventionand should not be construed to limit the scope of the invention of thepresent application in any way.

EXAMPLE 1

To demonstrate the effectiveness of the solvent compositions of thepresent invention in speeding the rate of drying of nail enamels, acommercially available red nail enamel sold under the trademark L'OREAL"Drumbeat" was obtained and the solvents distilled therefrom. Thesolvents were replaced by a solvent system containing 28.28 percentacetone in combination with additional solvents, includingmethylchloroform, ethyl acetate, toluene butyl acetate and isopropanolin the following weight ratios:

    ______________________________________                                                 Weight Percent of                                                                            Weight Percent of                                              Solvent in Solvent                                                                           Solvent in Composi-                                            System (By Weight of                                                                         tion Based on Solids                                  Solvent  Solvent)       Weight Percent of 37.5%                               ______________________________________                                        Acetone  28.28%         17.68%                                                Isopropanol                                                                            2.02%          1.26%                                                 Ethyl Acetate                                                                          39.94%         24.96%                                                Toluene  28.81%         18.01%                                                Butyl Acetate                                                                          0.74           0.46%                                                 Methyl   0.21           0.13%                                                 Chloroform                                                                    ______________________________________                                    

Results: The L'Oreal product "drumbeat" was evaporated to near drynessand the solvent system including 17.68% by weight acetone was added tothe solids remaining after evaporation. The resulting suspension wasshaken vigorously until a homogeneous suspension was realized. Theviscosity was slightly thin, too thin to be commercialized. The dryingtime of the nail polish formulation was 70 seconds on plate glass. Incomparison, the drying time of the L'Oreal product was greater than 4minutes.

Examples 2-10

In the following examples, a number of solvent combinations containingat least 4.5% by weight of acetone were used to produce a number of nailenamel compositions using a standard base formulation. In each case, thedrying time of the formulations was significantly less than 3 minutes.

    ______________________________________                                        Non-Volatile Component (Solids)                                                                    Weight Percent of                                        Component            Final Composition                                        ______________________________________                                        Primary Film-Forming Polymer                                                                       10.5%                                                    Nitrocellulose RS 1/2 Sec.                                                    Secondary Film-Forming Polymer                                                                     9.0                                                      Toluenesulfonamide formaldehyde                                               Plasticizer                                                                   Camphor              0.4%                                                     Dibutylphthalate     4.1%                                                     Bentone RSNC ™    12.0%                                                    Stearalkonium hectorite (25%)                                                 Nitrocellulose                                                                Camphor                                                                       ______________________________________                                    

Procedure: To produce nail enamel compositions, the components listedabove were added step-wise, in the order 1) primary film-formingpolymer; 2) secondary film-forming polymer and 3) plasticizer to thebelow-described solvent systems. Each component was added and mixeduntil a homogeneous solution was produced. After the first threecomponents were added, the Bentone RSNC™ was added and the resultingmixture was mixed under high shearing force with a laboratory mixer forat least about 1 hour until a homogeneous gel was obtained. Pigments areadded with further mixing. The resulting compositions were then "drawndown" on lineta cards to determine drying times. Drying times weredetermined by placing a cotton swab (Q-tips from Cheseborough Ponds,U.S.A.) on the surface. An absence of sticking of cotton swabs to thefilm was considered dry for purposes of the present invention. Thedrying times of the individual experiments are presented as indicated.

All formulations evidenced acceptable viscosities and an absence ofstreaking. To determine static viscosities, compositions were allowed tostand for at least 24 hours in a constant temperature bath at 25° C.Static viscosity tests were performed using a Brookfield LVF, spindle #3at 12 RPM and 25° C. To determine static viscosity the dial reading wasmultiplied by a factor to determine approximate viscosity (e.g.,16×100=800 cps). It should be noted that the static viscosities weredetermined in the following experiments with a Brookfield LVF, spindle#3, but are defined in the general invention using a Brookfield RVF,spindle #3 as those of ordinary skill in the art would define them.Because access to a Brookfield RVF was not available, the staticviscosities in the following invention are presented using the availableBrookfield LVF instrumentation. The compositions of the presentinvention have acceptable viscosities.

Shaken viscosities were determined on a Brookfield LVF using Spindle #3at 25° C.

a) at 60 RPM. To determine viscosity dial reading was multiplied by afactor to determine approximate viscosity (e.g., 20×20=400 cps).

b) at 6 RPM. To determine viscosity dial reading was multiplied by afactor to determine approximately (e.g., 5×200=1000 cps).

Because of the nature of the viscosity determination, and may dependupon the amount of shaking done (variable), shaken viscosities arebelieved to be less reliable than are the static viscosities.

Example 2

    ______________________________________                                        Solvent System #1                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.1%                                                          Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              0.64                                                           Methylchloroform                                                                             18.44                                                          ______________________________________                                    

Results Composition including solids were formulated as described aboveusing 64% by weight of solvent system #1 and 36% by weight ofNon-Volatile Component as described above. Drying time on lineta cards(3 mm draw down) at an ambient temperature of 68.4° F. (20.2° C.) and arelative humidity of about 40% was 51 seconds. Drying time in a relativehumidity of about 65-70% was 90 seconds. Static viscosity of theformulation was 1201 cps. Shaken viscosity at 60 RPM was 504 cps and at6 RPM was 600 cps.

Example 3

    ______________________________________                                        Solvent System #2                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              18.75%                                                         Methylchloroform                                                                             18.44                                                          ______________________________________                                    

Results: Absence of acetone to determine effect of acetone on dryingtimes. Composition including solids were formulated as described aboveusing 64% by weight of solvent system #2 and 36% by weight ofNon-Volatile Component as described above. Drying time on lineta cards(3 mm draw down) at an ambient temperature of 68.4° F. (20.2° C.) and arelative humidity of about 40% was 3 minutes and 17 seconds. Drying timein a relative humidity of about 65-70% is about 4.5 to 5 minutes. Staticviscosity of the formulation was 970 cps. Shaken viscosity at 60 RPM was626 cps and at 6 RPM was 720 cps.

Example 4

    ______________________________________                                        Solvent System #3                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Isopropanol    1.28                                                           Ethyl Acetate  43.96%                                                         N-Butyl Acetate                                                                              18.75%                                                         ______________________________________                                    

Results: Absence of acetone and methylchloroform to determine effect ofacetone and methylchloroform on drying times. Composition includingsolids were formulated as described above using 64% by weight of solventsystem #3 and 36% by weight of Non-Volatile Component as describedabove. Drying time on lineta cards (3 mm draw down) at an ambienttemperature of 68.4° F. (20.2° C.) and a relative humidity of about 40%was 3 minutes and 9 seconds. Drying time in a relative humidity of about65-70% is about 4.5 to 5 minutes. Static viscosity of the formulationwas 1950. Shaken viscosity at 60 RPM was 700 cps and at 6 RPM was 740cps.

Example 5

    ______________________________________                                        Solvent System #4                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.11%                                                         Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              0.51%                                                          Methylchloroform                                                                             0.13%                                                          Methylene Chloride                                                                           18.43%                                                         ______________________________________                                    

Results: Experiment to replace toluene with methylene chloride.Composition including solids were formulated as described above using64% by weight of solvent system #4 and 36% by weight of Non-VolatileComponent as described above. Viscosities were in acceptable range.Drying time on lineta cards (3 mm draw down) at an ambient temperatureof 70° F. (21.5° C.) and a relative humidity of about 50% was 64seconds. Drying time in a relative humidity of about 65-70% issignificantly less than three minutes. Static viscosity of theformulation was 1750 cps. Shaken viscosity at 60 RPM was 936 cps and at6 RPM was 2000 cps.

Example 6

    ______________________________________                                        Solvent System #5                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.11%                                                         Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              0.51%                                                          Methylchloroform                                                                             0.13%                                                          Methylethyl ketone                                                                           18.43%                                                         ______________________________________                                    

Results: Experiment to replace toluene with methylethyl ketone.Composition including solids were formulated as described above using64% by weight of solvent system #5 and 36% by weight of Non-VolatileComponent as described above. Drying time on lineta cards (3 mm drawdown) at an ambient temperature of 70° F. (21.5° C.) and a relativehumidity of about 50% was 79 seconds. Drying time in a relative humidityof about 65-70% is significantly less than 3 minutes. Static viscosityof the formulation was 1470 cps. Shaken viscosity at 60 RPM was 624 cpsand at 6 RPM was 1120 cps.

Example 7

    ______________________________________                                        Solvent System #6                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.11%                                                         Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              0.51%                                                          Methylchloroform                                                                             0.13%                                                          Hexane         18.43%                                                         ______________________________________                                    

Results: Experiment to replace toluene with hexane. Compositionincluding solids were formulated as described above using 64% by weightof solvent system #6 and 36% by weight of Non-Volatile Component asdescribed above. Drying time on lineta cards (3 mm draw down) at anambient temperature of 70° F. (21.5° C.) and a relative humidity ofabout 50% was 77 seconds. Drying time in a relative humidity of about65-70% is significantly less than 3 minutes. Static viscosity of theformulation was 930 cps. Shaken viscosity at 60 RPM was 710 cps and at 6RPM was 300 cps.

Example 8

    ______________________________________                                        Solvent System #7                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.11%                                                         Isopropanol    1.28                                                           Ethyl Acetate  25.54%                                                         N-Butyl Acetate                                                                              0.51%                                                          Methylchloroform                                                                             0.13%                                                          Cyclohexane    18.43%                                                         ______________________________________                                    

Results: Experiment to replace toluene with cyclohexane. Compositionincluding solids were formulated as described above using 64% by weightof solvent system #7 and 36% by weight of Non-Volatile Component asdescribed above. Drying time on lineta cards (3 mm draw down) at anambient temperature of 70° F. (21.5° C.) and a relative humidity ofabout 50% was 79 seconds. Drying time in a relative humidity of about65-70% is significantly less than 3 minutes. Static viscosity of theformulation was 1120 cps. Shaken viscosity was 704 cps at 60 RPM and 400cps at 6 RPM.

Example 9

    ______________________________________                                        Solvent System #8                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        4.5%                                                           Isopropanol    1.6                                                            Ethyl Acetate  33.16%                                                         Toluene        23.95%                                                         N-Butyl Acetate                                                                              0.66%                                                          Methylchloroform                                                                             0.13%                                                          ______________________________________                                    

Results: Experiment to determine effect of reduced acetone. Compositionincluding solids were formulated as described above using 64% by weightof solvent system #8 and 36% by weight of Non-Volatile Component asdescribed above. Drying time on lineta cards (3 mm draw down) at anambient temperature of 72.0° F. (23.0° C.) and a relative humidity ofabout 24% was 2 minutes. Drying time in a relative humidity of about50-55% is about 3 minutes.

Example 10

    ______________________________________                                        Solvent System #9                                                                            Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Isopropanol    1.3                                                            Ethyl Acetate  25.5%                                                          N-Butyl Acetate                                                                              0.5%                                                           Methylchloroform                                                                             0.1%                                                           Methylene chloride                                                                           18.2                                                           ______________________________________                                    

Results: Experiment to determine effect of replacement of acetone with asolvent, methylene chloride, that has a much lower boiling point thanacetone. Experiment was performed to determine if interaction of lowerboiling solvents with other solvents in mixture was responsible for fastdrying times. Composition including solids were formulated as describedabove using 64% by weight of solvent system #9 and 36% by weight ofNon-Volatile Component as described above. Drying time on lineta cards(3 mm draw down) at an ambient temperature of 64° F. (17.8° C.) and arelative humidity of about 37% was 3 minutes and 21 seconds. Drying timein a relative humidity of about 65-70% is about 5 minutes.

Example 11

    ______________________________________                                        Solvent System #10                                                                           Percent By Weight of                                           Solvent        Final Composition                                              ______________________________________                                        Acetone        18.2                                                           Isopropanol    1.3                                                            Ethyl Acetate  25.5%                                                          Toluene        18.4%                                                          N-Butyl Acetate                                                                              0.5%                                                           Methylchloroform                                                                             0.1%                                                           ______________________________________                                    

Results: Composition including solids are formulated as described aboveusing 64% by weight of solvent system #10 and 36% by weight ofNon-Volatile Component as described above. Drying time on lineta cards(3 mm draw down) at an ambient temperature of 72.7° F. (23.3° C.) and arelative humidity of about 55% is less than 60 seconds. Drying time in arelative humidity of about 65-70% is significantly less than 3 minutes.

This invention has been described in terms of specific embodiments setforth in detail herein, but it should be understood that these are byway of illustration and the invention is not necessarily limitedthereto. Modifications and variations will be apparent from thedisclosure and may be resorted to without departing from the spirit ofthe inventions those of skill in the art will readily understand.Accordingly, such variations and modifications are considered to bewithin the purview and scope of the invention and the following claims.

We claim:
 1. A quick-dry nail enamel composition for coating natural andsynthetic nails of animals and humans comprising:a) about 5% to about25% by weight of a primary film-forming polymer; b) about 4% to about13% by weight of a secondary film-forming polymer; c) about 2.0% toabout 7.5% by weight of at least one plasticizer; d) an amount of atleast one thixotropic agent effective to produce gelling of saidcomposition; e) about 0.025 to about 4.0% of at least one pigment; andf) an amount of acetone ranging from about 4.5% to about 35% by weightof said composition in combination with at least one additional solventhaving sufficient polarity in combination with said acetone to dissolvesaid primary and secondary film-forming polymers and said plasticizer toproduce a stable composition having a static viscosity ranging fromabout 400 to about 1200 centipoises, said composition drying on anatural or synthetic nail within a period of less than about threeminutes.
 2. The composition according to claim 1 wherein said primaryfilm-forming polymer is nitrocellulose.
 3. The composition according toclaim 1 wherein said secondary film-forming polymer is nitrocellulose.4. The composition according to claim 1 wherein said plasticizer isselected from the group consisting of dibutyl phthalate, camphor andmixtures thereof.
 5. The composition according to claim 4 wherein saidplasticizer is a mixture comprising dibutylphthalate and camphor.
 6. Thecomposition according to claim 1 wherein said additional solvent isselected from the group consisting of ethyl acetate, methyl acetate,methanol, ethanol, isopropanol, n-butanol, n-butyl acetate,methylchloroform, methylene chloride, methylethylketone, toluene,xylene, aromatic solvents, amyl acetate, hydrocarbons including pentane,hexane, cyclopentane and cyclohexane, 1,4-dioxane, tetrahydrofuran andmixtures thereof.
 7. The composition according to claim 1 wherein saidprimary film-forming polymer is nitrocellulose, said secondaryfilm-forming polymer is toluene solufonamideformaldehyde resin, saidplasticizer is a mixture of dibutylphthalate and camphor, saidadditional solvent is a mixture containing at least two solventsselected from the group consisting of ethyl acetate, methyl acetate,ethanol, isopropanol, toluene, n-butyl acetate, methylchloroform,methylene chloride, hexane, cyclohexane and methylethylketone.
 8. Thecomposition according to claim 7 wherein said additional solventcomprises at least one ester selected from ethyl acetate, n-butylacetate, methylacetate and mixtures thereof in an amount ranging fromabout 20% to about 30% by weight of said composition.
 9. A nail enamelcomposition for coating natural and synthetic nails of animals andhumans, comprising:a) an amount of nitrocellulose as a primaryfilm-forming polymer ranging from about 5% to about 25% by weight ofsaid composition; b) an amount of toluene-sulfonamide formaldehyde resinas a secondary film-forming polymer ranging from about 4% to about 13%by weight of said composition; c) an amount of at least one plasticizerselected from the group consisting of dibutyl phthalate, camphor andmixtures thereof in an amount from about 2.0% to about 10% by weight ofsaid composition; d) an amount of an organoclay thixotropic agenteffective to produce gelling of said composition; e) at least onepigment in an amount ranging from about 0.025 to about 4% by weight ofsaid composition; and f) a solvent combination comprising an amount ofacetone ranging from about 15% to about 35% by weight of saidcomposition in combination with at least one alcohol selected from thegroup consisting of ethanol, isopropanol and n-butanol and at least oneester selected from the group consisting of methyl acetate, ethylacetate, propyl acetate, n-butyl acetate and amyl acetate, said solventcombination dissolving said primary film-forming polymer and saidsecondary film-forming polymer and producing a gelled composition incombination with said organoclay thixotropic agent having a staticviscosity ranging from about 400 to about 1200 centipoises, saidcomposition drying on a natural or synthetic nail to a durable, flexiblecoating.
 10. The composition according to claim 9 wherein said alcoholis isopropanol.
 11. The composition according to claim 10 wherein saidester includes ethyl acetate and n-butyl acetate.
 12. A solvent systemfor use in a nail enamel composition comprising about 5% to about 25% byweight of a primary film-forming polymer, about 4% to about 13% byweight of a secondary film forming polymer, about 2.0% to about 7.5% byweight of at least one plasticizer, an amount of a thixotropic agenteffective to produce gelling of said composition, about 0.025 to about4.0% by weight of at least one pigment and the remainder of saidcomposition comprising said solvent system, said solvent systemcomprising acetone in an amount ranging from about 6% to about 70% byweight of said solvent system and at least one additional solvent, saidsolvent system having sufficient polarity to dissolve said primary andsecondary film-forming polymers and said plasticizer to produce a stablenail enamel composition comprising acetone in an amount ranging fromabout 4.5% to about 35% by weight and having a static viscosity rangingfrom about 400 to about 1200 centipoises, said nail enamel compositiondrying on a natural or synthetic nail within a period of less than aboutthree minutes.